Thursday, August 28, 2008

Cut to the Chase: Portable Scope

I'll post more articles in the future about what you do and don't want in a telescope, but for now I'll give some specific recommendations. First, I'll recommend some scopes that are especially portable.

These are good if you need something small and easy to take with you, or you have very little space for storing a telescope between observing sessions.

First, I recommend the Meade ETX series Maksutov-Cassegrains. These presently include the ETX-90, ETX-105, and ETX-125. Different versions have different letters after the model name to indicate what features that specific model includes. I own an ETX-90RA, one of the earliest models. It includes a clock drive, but no guidance computer or other electronics. Newer models have replaced the RA, so these aren't available new any more.

On these, I recommend learning to use them without having to have the computer guide the telescope. Simply use the hand controller as you would a set of mechanical slow motion controls for pointing the telescope at first. Later, learn to use the computer drive as a clock drive to keep the telescope on an object once it is in view. This will require learning to do a "north alignment" on the telescope.

I don't give the instructions for doing so here since different versions of the computer-controlled ETXs use different software versions that do it differently. Also, I don't know how to do it specifically, I only know it's possible.

Once you've learned to align the scope, you should be able to use the computer to direct the scope toward objects as well. But it will be easier to learn how if you're already familiar with the objects you direct it toward while you're learning how to use the computer. So if you've already learned how to find some objects on your own without the computer, you will know whether the computer is doing what you want when you are figuring out how to use it.

For goodness sake, whatever you do, don't expect to invite a bunch of people out to see the sky on the first night you take the telescope out. There's nothing worse than trying to learn how to use the computer while a bunch of people are waiting on you to show them amazing things in the sky, especially if you don't know Altair from Antares! Expect to spend some time on your own figuring things out, and expect nothing but a list of questions from your first experience.

Set things up inside in the light first so you can learn the controls and familiarize yourself with the menus. Then go into the yard someplace where it's easy to go back inside and refer to a good website (like Mike Weasner's excellent ETX site) to find out why things aren't working the way you expect.

Once you've had a couple of successful sessions on your own, you'll be ready to invite others over for a look.

Even better than the ETXs, since they don't have computers on them, are the wonderful wide field refractors made by Stellarvue. These are not the refractors you see in discount stores. They're a whole different animal. Well made, easy to use, high performance. They come in a number of different packages with mounts and accessories. They can show you things you didn't know you could see in a scope that size. The images I've seen in every Stellarvue I've looked through have been excellent. The price of an SV80 is comparable to the price of an ETX, but the SV80 comes with a lot more "fit and finish" if you know what I mean. And the Stardust Blue coatings just emanate a feeling of "classy."

Plus the Stellarvues come with an excellent case. I paid over $100 extra for a nice case for my ETX, since all it came with was a cardboard box with a styrofoam insert.

You can get them with a computer controlled mount if you insist. ;) But I'd recommend learning to use the scope without a computer, first. Besides, when you've got such a fine little scope in front of you why let a computer get between you and the sky? (You can always add it later by upgrading your mount.)

What's nice about scopes this size as a first scope is that even if you get a larger scope later the small scope won't just become a dust collector. There'll be plenty of times when the big scope isn't convenient to have along. A small scope packs along easily. I have a large pair of binoculars that used to come with me when I travelled. Now my small scope does. I actually got my small scope after I got a larger scope. I now have two larger scopes, I'm building a third and fourth, but my light, little, easy to pack scope will never go unused. I even use it at home when I don't have enough energy to haul the big scopes all the way to the patio.

For accessories, you're going to want to get a good, solid, easy to use travel case. The Stellarvues have you covered here. For ETXs I recommend the after-market case made by JMI. I picked up a closeout/overstock case from them for a discount, and I love it. The Meade hard case is pretty good, too, but I have a preference for the one from JMI. The finder that comes with the ETX needs replacing, too. The little telescope thing represents everything I hate in commercial pack-in finder scopes. Get a nice red-dot finder or a Telrad. Granted, the Telrad is almost as large as the scope, but believe me the scope's not worth a darn if you can't get it pointed at what you want to look at. The

Stellarvue comes with a red dot finder, so once again, you're already covered at no extra expense. Plus the Stellarvue has a wider field of view than the ETX, making it easier to get objects in the eyepiece.

I'll post another article on the economics of a scope purchase, then I'll post my recommendations for a larger first telescope.
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